I was pleasantly surprised when I saw a hdparm module as part of grub2. So I tried the -X <transfer mode> parameter as is provided by the linux command line finding it isn't implemented. eg:
# hdparm -X udma5 /dev/sda
Can the development team consider adding this feature? A number of ppl's bios is incorrectly setting interfaces to UDMA2/MDMA2, particularly on pata optical drive interfaces which users are using a 2.5" HDDs instead via an optical bay caddy. The workaround being to wait for a (slow) Linux/Windows boot and then typing the above commandline. Doing this at the grub2 bootloader level being more preferable.